197861557 has 2 divisors, whose sum is σ = 197861558. Its totient is φ = 197861556.

The previous prime is 197861549. The next prime is 197861563. The reversal of 197861557 is 755168791.

It is a happy number.

197861557 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 195272676 + 2588881 = 13974^2 + 1609^2 .

It is a cyclic number.

It is not a de Polignac number, because 197861557 - 2³ = 197861549 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 197861557.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (197861537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98930778 + 98930779.

It is an arithmetic number, because the mean of its divisors is an integer number (98930779).

Almost surely, 2^197861557 is an apocalyptic number.

It is an amenable number.

197861557 is a deficient number, since it is larger than the sum of its proper divisors (1).

197861557 is an equidigital number, since it uses as much as digits as its factorization.

197861557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 529200, while the sum is 49.

The square root of 197861557 is about 14066.3270614614. The cubic root of 197861557 is about 582.7117929149.

The spelling of 197861557 in words is "one hundred ninety-seven million, eight hundred sixty-one thousand, five hundred fifty-seven".